1. Field of the Invention
This invention relates to a connector, and more particularly to a connector of the type in which each of the terminals, inserted respectively into corresponding terminal receiving chambers arranged in predetermined columns and rows in a connector housing, is retained in a double manner by a first retaining means, which is formed integrally with the connector housing, and projects into the associated terminal receiving chamber, and a second retaining means attached to the connector housing from an outer peripheral surface of the connector housing.
2. Related Art
A wire harness, heretofore used in electric circuits in an automobile, is connected at one end to various electric devices by male and female connectors fitted together. At such a portion as an instrument panel where many switches and instruments are provided in a concentrated manner, a large number of connectors are provided, and much time and labor are required for connecting these connectors, and besides a considerable space is occupied by the connectors. Under the circumstances, there has been used a connector of the complex type, and more specifically a plurality of connectors, receiving respective terminals of different sizes and shapes, have been combined together into a single connector by which a large number of electrical connections are made.
FIGS. 7 to 9 show such a conventional complex-type connector (see Japanese Patent Unexamined Publication No. 62-188186).
As shown in FIG. 7, this complex-type connector comprises a male connector housing 1 and a female connector housing (not shown) which are fitted together, thereby electrically connecting terminals, held in the male connecter housing, respectively to terminals held in the female connector housing.
The male connector housing 1 has terminal receiving chambers 8 and 9 arranged in predetermined columns and rows for respectively receiving two kinds of female terminals 3 and 4. Similarly, the female connector housing (not shown) has two kinds of terminal receiving chambers arranged in predetermined columns and rows for respectively receiving male terminals corresponding respectively to the female terminals 3 and 4 (That is, the male and female terminals are fitted together).
The number of terminals received and held by the male and female connector housings is large, and a considerable force is required for fitting the two connector housings together. Therefore, the fitting connection between the male and female connector housings is achieved by threading a tightening bolt (not shown) (which passes through a bolt mounting portion extending through a central portion of the female connector housing in the same direction as the direction of extension of the terminal receiving chambers) into an internally-threaded member (nut) 14 mounted at a central portion of the male connector housing 1.
The male and female connector housing have double-retaining mechanisms, respectively, and these double-retaining mechanisms are similar in construction to each other, and therefore the double-retaining mechanism of the male connector housing will be described below.
The female terminal 3 is smaller in width than the female terminal 4, and in the male connector housing 1, the narrower female terminals 3 are inserted respectively into three rows of terminal receiving chambers 8 counting from the right and left side edge of this connector housing, while the wider female terminals 4 are inserted respectively into three rows of terminal receiving chambers 9 provided at a central portion of this connector housing. The terminal receiving chambers 8 and 9 are so arranged that the terminals 3 and 4 received in these chambers are arranged or oriented differently from each other, for example, with base plate portions of the terminals 3 and 4 disposed perpendicularly to each other. As shown in FIG. 9, a first retaining means, such as a lance 16, 17, for engagement with an electrical contact portion 3a, 4a of the inserted female terminal 3, 4 to retain the terminal against withdrawal is formed within the terminal receiving chamber 8, 9.
Retaining pin insertion holes 19 and 20, each communicating the corresponding terminal receiving chambers in the same row with one another, are open to an outer peripheral surface of the male connector housing 1 in corresponding relation to the rows of terminal receiving chambers.
The retaining pin insertion holes 19 and 20 are used for attaching second insertion retaining means 22. As shown in FIG. 7, each of the second insertion retaining means 22 comprises a plurality of retaining pins 23 and 24 for insertion respectively into the associated retaining pin insertion holes 19 and 20 to retain the terminals 3 and 4 received respectively in the terminal receiving chambers 8 and 9, and a connecting portion 26 interconnecting proximal ends of these retaining pans 23 and 24 at intervals (pitch) corresponding to the intervals of the rows of retaining pin insertion holes 19 and 20 formed in the connector housing 1.
As shown in FIG. 9, the lance 16 engages a stamped hole in the base plate portion of the electrical contact portion 3a of the female terminal 3 to prevent withdrawal of the female terminal 3 received in the terminal receiving chamber 8. The retaining pin 23 of the second insertion retaining means 22 has a rhombic transverse cross-section, and a distal end of the retaining pin 23 engages a step portion at a rear end of the electrical contact portion 3a, received in the terminal receiving chamber 8, to retain the female terminal 3 already retained by the lance 16 to achieve the double retainment, thereby positively preventing withdrawal of the terminal 3.
The retaining pin 24 of the second insertion retaining means 22 has a rectangular transverse cross-section, and the adjacent retaining pins 24 hold a constricted neck portion 4a of the female terminal 4 to retain the same, thereby achieving the double retainment.
Namely, in the connector housing 1, the female terminals 3 and 4 are inserted into the respective terminal receiving chambers 8 and 9, and then the second insertion retaining means 22 are attached to the connector housing 1 respectively from the upper and lower sides of the outer peripheral surface thereof to retain the received female terminals 3 and 4 in a double manner, thereby preventing withdrawal of the female terminals 3 and 4 more positively.
As described above, the second insertion retaining means 22 for double retaining purposes are attached to the connector housing 1 after the female terminals 3 and 4 are inserted respectively into the terminal receiving chambers 8 and 9. At this time, if the female terminal 3, 4 fails to be completely inserted into a predetermined position where the female terminal is retained by the lance 16, 17, that is, the terminal 3 is in a half-inserted condition, the retaining pin 23, 24 of the subsequently-inserted second insertion retaining means 22 abuts at its distal end against the side of the half-inserted female terminal 3, 4. If the retaining pins 23 and 24 are inserted with a large force, there has been encountered a problem that the half-inserted female terminal 3, 4 or the retaining pin 23, 24 are so damaged that it is difficult to repair the damaged portion.
Furthermore, even if the operator detects the half-inserted condition of the female terminals 3, 4 through a sensation obtained when the retaining pins 23, 24 abuts against the half-inserted female terminal 3, 4, there is needed a cumbersome operation for correcting such a condition, in which the inserted retaining pins 23, 24 are withdrawn, and then are again brought into a completely-inserted condition after the female terminals are fully inserted. This results in a problem that the efficiency of the connector-assembling operation is lowered.